[PATCH] Make git-reset delete empty directories

[PATCH] Make git-reset delete empty directories

[Shawn Pearce]

When git-reset --hard is used and a subdirectory becomes
empty (as it contains no tracked files in the target tree)
the empty subdirectory should be removed.  This matches
the behavior of git-checkout-index and git-read-tree -m
which would not have created the subdirectory or would
have deleted it when updating the working directory.

Subdirectories which are not empty will be left behind.
This may happen if the subdirectory still contains object
files from the user's build process (for example).

---

 git-reset.sh     |   17 ++++++++++++---
 t/t7101-reset.sh |   63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100755 t/t7101-reset.sh

base 3397f9df53092871de2c33c143f1f4413654c40d
last 9e4158a26134a05e6011613976e26e7bfa813aca
diff --git a/git-reset.sh b/git-reset.sh
index fe53fc8065dc82c0054ba9891b28a00b0752bf87..8eac4640bc8dfb655f8429036b68644df027dea4 100755
--- a/git-reset.sh
+++ b/git-reset.sh
@@ -74,22 +74,33 @@ case "$reset_type" in
 	git-ls-files --cached -z |
 	perl -e '
 		use strict;
-		my (%keep, $fh);
+		my (%keep_file, %keep_dir, %rm_dir, $fh);
 		$/ = "\0";
 		while (<STDIN>) {
 			chomp;
-			$keep{$_} = 1;
+			$keep_file{$_} = 1;
+			while (s,/?[^/]+$,, && $_) {
+				last if $keep_dir{$_}++;
+			}
 		}
 		open $fh, "<", $ARGV[0]
 			or die "cannot open $ARGV[0]";
 		while (<$fh>) {
 			chomp;
-			if (! exists $keep{$_}) {
+			if (! exists $keep_file{$_}) {
 				# it is ok if this fails -- it may already
 				# have been culled by checkout-index.
 				unlink $_;
+				while (s,/?[^/]+$,, && $_ && !$keep_dir{$_}) {
+					last if $rm_dir{$_}++;
+				}
 			}
 		}
+		foreach (sort {length($b) <=> length($a)} keys %rm_dir) {
+			# it is ok if this fails -- it may have user files
+			# we do not track and thus should not delete.
+			rmdir $_;
+		}
 	' $tmp-exists
 	;;
 --soft )
diff --git a/t/t7101-reset.sh b/t/t7101-reset.sh
new file mode 100755
index 0000000000000000000000000000000000000000..a9191407f21c748f4c00bf909f670fc2b5124ec3
--- /dev/null
+++ b/t/t7101-reset.sh
@@ -0,0 +1,63 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Shawn Pearce
+#
+
+test_description='git-reset should cull empty subdirs'
+. ./test-lib.sh
+
+test_expect_success \
+    'creating initial files' \
+    'mkdir path0 &&
+     cp ../../COPYING path0/COPYING &&
+     git-add path0/COPYING &&
+     git-commit -m add -a'
+
+test_expect_success \
+    'creating second files' \
+    'mkdir path1 &&
+     mkdir path1/path2 &&
+     cp ../../COPYING path1/path2/COPYING &&
+     cp ../../COPYING path1/COPYING &&
+     cp ../../COPYING COPYING &&
+     cp ../../COPYING path0/COPYING-TOO &&
+     git-add path1/path2/COPYING &&
+     git-add path1/COPYING &&
+     git-add COPYING &&
+     git-add path0/COPYING-TOO &&
+     git-commit -m change -a'
+
+test_expect_success \
+    'resetting tree HEAD^' \
+    'git-reset --hard HEAD^'
+
+test_expect_success \
+    'checking initial files exist after rewind' \
+    'test -d path0 &&
+     test -f path0/COPYING'
+
+test_expect_failure \
+    'checking lack of path1/path2/COPYING' \
+    'test -f path1/path2/COPYING'
+
+test_expect_failure \
+    'checking lack of path1/COPYING' \
+    'test -f path1/COPYING'
+
+test_expect_failure \
+    'checking lack of COPYING' \
+    'test -f COPYING'
+
+test_expect_failure \
+    'checking checking lack of path1/COPYING-TOO' \
+    'test -f path0/COPYING-TOO'
+
+test_expect_failure \
+    'checking lack of path1/path2' \
+    'test -d path1/path2'
+
+test_expect_failure \
+    'checking lack of path1' \
+    'test -d path1'
+
+test_done

Re: [PATCH] Make git-reset delete empty directories

[Junio C Hamano]

Shawn Pearce <spearce@spearce.org> writes:

> When git-reset --hard is used and a subdirectory becomes
> empty (as it contains no tracked files in the target tree)
> the empty subdirectory should be removed.

I thought I said it would be a few-liner, but it appears I did
not send that message.

This untested one is far simpler, if less efficient, isn't it?

---

diff --git a/git-reset.sh b/git-reset.sh
index fe53fc8..195d043 100755
--- a/git-reset.sh
+++ b/git-reset.sh
@@ -88,6 +88,9 @@ case "$reset_type" in
 				# it is ok if this fails -- it may already
 				# have been culled by checkout-index.
 				unlink $_;
+				while (s|/[^/]*$|| && $_ ne "") {
+					rmdir($_) or last;
+				}
 			}
 		}
 	' $tmp-exists

Re: [PATCH] Make git-reset delete empty directories

[Shawn Pearce]

Junio C Hamano <junkio@cox.net> wrote:
> I thought I said it would be a few-liner, but it appears I did
> not send that message.

You did.  Somehow I forgot that request.  I wrote a simple approach
similar to what you show below then tried to make it slightly
more efficient by only attempting to delete each directory once.
Obviously that wasn't wise on my part.  :-)
 
> This untested one is far simpler, if less efficient, isn't it?
> 
> ---
> 
> diff --git a/git-reset.sh b/git-reset.sh
> index fe53fc8..195d043 100755
> --- a/git-reset.sh
> +++ b/git-reset.sh
> @@ -88,6 +88,9 @@ case "$reset_type" in
>  				# it is ok if this fails -- it may already
>  				# have been culled by checkout-index.
>  				unlink $_;
> +				while (s|/[^/]*$|| && $_ ne "") {
> +					rmdir($_) or last;
> +				}
>  			}
>  		}
>  	' $tmp-exists

I just ran it through the test script (t7101-reset.sh) that I
included in my patch and it passed, so clearly the version above
would be the better version to include.

Since it was untested before you are welcome to include the test
script with your version.  :-)

-- 
Shawn.

Re: [PATCH] Make git-reset delete empty directories

[Shawn Pearce]

Shawn Pearce <spearce@spearce.org> wrote:
> Junio C Hamano <junkio@cox.net> wrote:
> > I thought I said it would be a few-liner, but it appears I did
> > not send that message.

Actually its only a one line change if you accept Perl as Perl,
but not everyone likes having their loops do nothing in the loop
body whilest the condition does all of the work.

---
diff --git a/git-reset.sh b/git-reset.sh
index fe53fc8..e6471c0 100755
--- a/git-reset.sh
+++ b/git-reset.sh
@@ -88,6 +88,7 @@ case "$reset_type" in
                                # it is ok if this fails -- it may already
                                # have been culled by checkout-index.
                                unlink $_;
+                               1 while (s,/[^/]*$,, && rmdir $_);
                        }
                }
        ' $tmp-exists